Temperature-indicator.



. SWANSON.

TEMPERATURE INDICATOR. APPLICATION FILED SEPT. 21, 1914.

Patented June 22, 1915.

mains PATENT oration ERNEST J'. SWANSON, OF CHICAGO, ILLINOIS, ASSIGNQE T0 STEWART-WARNER SPEED- QMETEB CORPORATION,

or cnroaeo, ILLINOIS, A oo'nronarron or vmemm.

rnmrnna'ronn-mnioaron.

JLMLTAMW.

To all whom it may concern:

Be it known that 1, Banner J. SWANBON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Temperature-Indicators, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

This invention relates to temperature indicators and is particularly concerned with an improved form of indicating means-- therefor.

It consists of the features and elements described and shown in the drawings, as indicated by the claims.

Tn the drawings Figure 1 is a front elevation of a temperature indicator embodying this invention.- Fig. 2 is a front elevation of the background plate of the indicating means. Fig. 3- is a front elevation of'the apertured dial plate of the indicating means. Fig. l is a front elevation similar to Fig. 1 but showing the indicating needle in a different position.

The type of temperature indicator used for purposes of illustration is one whlch is particularly designed for use in connection with internal combustion engines, being intended to be mounted in the cooling water circuit, so as to indicate the temperature of the cooling water as it comes from the engine and thus indirectly indicate the. cond1- tion of the engine itself as to temperature. When employed on automobile engines the device is usually mounted .on the radlator cap,'A, so that the body, B, of the instrument in" which is housed the thermally-responsive element, not 'shown,'may extend down into the water in the radiator, so as to be influenced by the temperature of such water. In the event that the cooling water level recedes somewhat below the bottom of the device, the body portion, B, will st ll remain immersed in warm water caught in the splash cup, C, which will be constantly filled and re-filled by the splashing of the water caused by motion of the vehicle. As the water in the upper portion of the radiator is the hottest water in the cooling circuit, having just come from the engine cylinders, its influence on the temperature 1nd1- cator furnishes a very reliable indication of the condition of the engine itself.

Theportion of the device which is visible Specification of Letters Patent.

. toral casing,

above the radiator cap, A, consists of a sec- D, in which there is pivotally mounted an index member in the form-of a needle, E, which, as will be understood, is mechanically connected to the thermally responsive element housed in the body portion,

B, so that in response to temperature change, this index needle, E, will swing through the range permitted by the limits of the sectoral casing, D. For some uses there would be provided in the casing, D, a dial plate graduated in degrees of temperature, but for the purposes of the automobile driver, it is not essential or desirable that he be informed of the temperature in terms of degrees Fahrenheit, but rather .that'he learn directly from the position of the index member, E, the conditions of temperature under which his engine is operating. For this purpose therefore, the range of travel of the index member, E, is' divided into four parts;

namely, the normal range within which thedriver with means for telling at a glance in which of these temperature ranges his en'- gine is, and furnishes such information both through the particular position of the index member, E, and through the particular color contrast which it forms with the background against which it is revealed in that position, as hereinafter described.

The casing, D, is provided with an apertured dial plate, F, mounted in front of the index-member, E, provided, as shown in the drawing, with three apertures, F F and F respectively. The aperture, F corresponds to therange of temperature in the" vicinity of freezing; the aperture,F corre- A Patented June 22, i915, Application filed September 21, 1914. Serial No. 862,810. l

sponds to temperatures in the vicinity of the j boiling point of water; and the middle aperture, F covers a range of temperatures within which the engine maybe safely operated. But as safety and eiiiciency are not synon ous, this middle window, or aperture meahs of colored backgrounds, G and. G,

- carried by the back plate, G, which is posi- 'tioned behind the lane of travel of the index member, E. e colored field, G corresponds to the too cool range of tem era- .ture, while the differently co ored fiel Gr", corresponds to normal and efiicient range of temperature.

. In order toconvey more shar ly the sugiestion of danger when the in ex member,

,.moves into either of-the limiting fi'elds covered by the apertures, F and F the tip of the index needle, E, which is revealed at said windows is preferably enlar ed to cir-,

cular format E and is given a right red color so as to showin sharp contrast against .the white background portion of the back plate,G, and to avoid the appearance of this red portion of the index atthe window,'F

the said window is offset from the other two so asto reveal a different portion of the inscarcely fail to note and understand the reading under such conditions.

I.cla1m: Y

- 1. In anindicator having an index mem-'. ber movable in response to change of temperature, a dial plate mounted in front of said index, having a luralit-y of apertures corresponding to di erent ranges of temperature and positioned to reveal difierent portions of the index during the travel of the latter. a v 4 2. In'an indicator having an index member movable in response to change of.tem-' is divided into two sections by travel 0 perature, a dial plate mounted in front of said index, havin a plurality of apertures corresponding to 'fierent ranges of temperature and positioned to reveal difierent portionsof the index during the travel of the latter, said different portions of the index being diiferently colored.

3. In an indicator having an index member movable in response to change of temperature, a dial plate mounted in-front of said index having a lurality of apertures corresponding to di erent ranges of' temperature and positioned to reveal different portions of the index during the travel of the latter, said difierent portions of the index being diiferently colored; and a background late mounted behind theplane of i the index and havin difierently colored portions positioned to show through the res ective apertures of the dial plate to form different color contrasts with the index member.

4. In an indicator having an index member movable inresponse'to' change of temperature, a dial plate mounted in front of said index having a fiplurality of apertures correspondingto di erent ranges of temperature and positioned to reveal different portions of the index during the travelof the latter, said different ortions of the index being difierently col ared, and a back late mounted behind the plane of differentl ow throng ground travel 0 the index and havingJ colored portions posi ioned to s the'respective apertu es of the dial plate to form dlfierent color contrasts with the index member; a plurality of such difierently' colored background sections being arranged to appear through one of the sai apertures.

11 testimong whereof, I have hereunto set my hand at hicago, 111., this 18th day of September, 1914.

ERNEST J. SWAN SON. Witnesses:

E. C. JAMISON,

J. GtGILMOBE. 

